0.72×7.2+2.7×0.28 =0.72x7.2+2.7x（1-0.72）=0.72x7.2+2.7-2.7x0.72 =2.7+0.72x（7.2-2.7） =2.7+0.72x4.5 =2.7+3.24 =5.94 谢谢，请采纳
